This invention relates to a method and bolt for supporting a structure such as a mine or tunnel roof or sidewall or the like. In presently known methods of anchoring for underground mines, tunnels, and the like it is necessary first to drill a hole in the structure to be consolidated, next to remove the drill from the hole, and then to place a bolt or other anchoring member in the hole. In the most common method of roof bolting, a bolt is inserted into the hole and is anchored tightly in place by means of expansion devices at or near its leading end. In another common method the anchoring member may fit in the hole with clearance, and the radial space between the anchoring member and the hole is filled with quick setting resinous materials, either along the entire length of the anchoring member or part of the way beginning at its leading end (the inner end of the hole). Recently other techniques have been pursued experimentally, and they are now in various stages of development. All currently used methods, however, require the separate operation of drilling a hole and removing the drill before the anchoring member can be placed within the structure that is to be supported.
The present invention eliminates the need for this separate step, and thus reduces the time and cost of the bolting operation, while increasing the safety of those who are performing it. This invention also achieves the desirable characteristics of gripping the structure along the entire length of the bolt, without the extra cost and time that are entailed in the use of resinous or other adhesives between the anchoring member and the structure to be consolidated.